Portal hypertension is the main prognostic factor in cirrhosis. The recent emergence of potent antiviral drugs and new algorithm of treatment for the management of complications due to portal hypertension have sensibly changed our perception of cirrhosis that can be now considered as a multistage liver disease whose mortality risk can be reduced by a tailored approachfor any stage of risk. Experts recommend to move toward a pathophysiological classification of cirrhosis that considers both structural and functional changes. The hepatic venous pressure gradient HVPG, is the reference gold standard to estimate the severity of portal hypertension in cirrhosis. It correlates with both structural and functional changes that occur in cirrhosis and carries valuable prognostic information to stratify the mortality risk. This article provides a general overview of the pathophysiology and natural course of cirrhosis and portal hypertension. We propose a simplified classification of cirrhosis based on low, intermediate and high mortality stage. The prognostic information provided by HVPG is presented according to each stage. A comparison with prognostic models based on clinical and endoscopic variables is discussed in order to evidence the additional contribute given by HVPG on top of other clinical and instrumental variables widely used in clinical practice. Portal hypertension is the main prognostic factor in cirrhosis. The recent emergence of potent antiviral drugs and new algorithm of treatment for the management of complications due to portal hypertension have sensibly changed our perception of cirrhosis that can be now considered as a multistage liver disease that mortality risk can be reduced by a tailored approach for any stage of risk. Experts recommend to move toward a pathophysiological classification of cirrhosis that considers both structural and functional changes. The hepatic venous pressure gradient HVPG, is the reference gold standard to estimate the severity of portal hypertension It correlates with both structural and functional changes that occur in cirrhosis and carries valuable prognostic information to stratify the mortality risk. This article provides a general overview of the pathophysiology and natural course of cirrhosis and portal hypertension. We propose a simplified classification of cirrhosis bas The prognostic information provided by HVPG is presented according to each stage. A comparison with prognostic models based on clinical and endoscopic variables is discussed in order to evidence the additional contribution given by HVPG on top of other clinical and instrumental variables widely used in clinical practice.